Thermostat



FIG. 1 is a front view of the thermostat design;

FIG. 2 is a rear view of the thermostat design;

FIG. 3 is a top view of the thermostat design;

FIG. 4 is a bottom view of the thermostat design;

FIG. 5 is a right side view of the thermostat design;

FIG. 6 is a left side view of the thermostat design; and,

FIG. 7 is a perspective view of the thermostat design. 

What is claimed is the ornamental design for a thermostat, as shown and described. 